US Patent 10551567 Broadband polarization beam splitter/combiner based on gradient waveguide directional coupler

A broadband polarization beam splitter/combiner based on a gradient waveguide directional coupler, comprises a gradient waveguide directional coupler, a beam combining end (1), a curved waveguide (5), a TE mode end (6) and a TM mode end (7). The coupler consists of a straight end gradient waveguide (2) and a serial end gradient waveguide (3). The trend of change of the gradient waveguide (2) is opposite to the gradient waveguide (3), and a gap is provided between the gradient waveguide (2) and the gradient waveguide (3). The beam combining end (1) is connected with one end of the gradient waveguide (2), the other end of the gradient waveguide (2) is connected with one end of the curved waveguide (5), the other end of the curved waveguide (5) is connected with the TE end (6), and the waveguide (3) is connected with the TM end (7).